The browser story in December mirrored the broader 2011 trends. After a surprising result in November, in which it held steady, Internet Explorer resumed normal service in December, with its market share continuing to fall. Chrome once more made gains, closing the gap with rival Firefox.

The story for 2011 as a whole was much the same. Internet Explorer lost 7.39 points of desktop market share over the course of the year. Firefox also fell over the year, losing 1.86 points in total. These browsers’ losses were WebKit’s gain: the two major WebKit-based browsers, Chrome and Safari, gained 8.75 and 0.95 points respectively. Opera too fell over the course of the year, finishing 2011 0.61 points lower than it closed 2010.

Chrome has become the alternative browser of choice. Firefox’s growth at Internet Explorer’s expense has been halted and now reversed, with large numbers of users defecting from both Microsoft’s and Mozilla’s browsers. Strong promotion, robust upgrading, and vigorous grassroots promotion of the browser have resulted in rapid adoption that shows no signs of slowing.

In the mobile market, Safari continues to rule.

Though Chrome’s automatic updates remain the best in the browser industry, its pool of non-upgrading users continues to be a significant feature. About 15 percent of Chrome users are using a version that’s at least two versions old. Though they only represent a small fraction of total Internet usage at the moment, this straggler demographic will grow as Chrome does.

Uptake of Firefox 8 appears to be going well, with users of the old Firefox 3.6 slowly moving away from that platform. Firefox too seems to have a straggler problem, again with about 15 percent of users on the “rapid release” track (versions 4 and higher) using an out-of-date version.

Microsoft is no stranger to the non-upgrading demographic, with considerable numbers of people using Internet Explorer 6 or 7 in spite of the availability of versions 8 and 9. The situation may start to improve shortly. Announced in mid-December, Microsoft is going to start shipping Internet Explorer as an automatic update to Windows Update users. Previously, Internet Explorer was an automatic update that required manual intervention to actually install; Windows Update would start an installation wizard that required the user to click through to install the browser. That wizard process has now been eliminated.

This month, users in Australia and Brazil will start to pick up the browser automatically. Assuming the rollout goes smoothly, Microsoft will expand the automatic deployments to other markets. Even when the switch is thrown globally, not all systems will be upgraded. Administrators will be able to block installation, and users who have previously rejected the upgrade won’t have their systems updated.

Nonetheless, this is a highly welcome change that should go a long way towards moving Internet Explorer users forward. Progress on that front is encouraging. Internet Explorer 6 saw a surprising increase in usage in November, but normal service was resumed in December, with both Internet Explorer 6 and 7 dropping to new lows of 7.66 and 4.87 percent, respectively.

In the US, usage of IE6 dropped below 1 percent for the first time since its 2001 release. The Czech Republic, Mexico, Portugal, Philippines, and Ukraine also hit the 1 percent threshold last month. These countries are joining an elite group of countries—Austria, Denmark, Finland, Norway, Poland, and Sweden—in which Internet Explorer 6 has below 1 percent of the market. Bringing up the rear is China, where the ancient browser still holds 25.2 percent of the market.

Our usage here at Ars showed small drops for Internet Explorer and Firefox, with small gains for Safari and Chrome. In mobile, the Android browser edged ahead of mobile Safari.